David Cameron today joined the long line of British prime ministers who go to European summits and return, like Roman generals, to declare a historic triumph. It's just that there is always a suspicious absence of gold, bejewelled elephants, or slaves to crucify along the roadside. In fact we've only got his word for it.

Mr Cameron adopted a more aggressive tone than his predecessors. The demand for a 6% rise in EU spending was "frankly outrageous" he said, before claiming that thanks to his negotiating skills and crafty alliances, he had made sure the increase was limited to 2.9% or even stalled for a year. This was, Ed Miliband said in one of his rare references to his Jewish roots, "chutzpah" – of a kind his grandmother would have admired.

The Labour leader, after some flabby performances, was on sparkly form. The prime minister, he said, was stuck between his old friends and his new friends on the frontbenches. "I want to say to him, very sincerely, we are here to help." He said this rather in the manner of Michael Howard's old TV catchphrase: "I'm not going to hurt you." It sends a shudder down the backbone, like trick or treating children when you've just given away the last funsize Snickers.

Why, the PM had wanted no rise at all in the budget, he had demanded a total freeze, then he went back to 2.9% – without apparently telling anyone. Now he was describing 2.9%, which was exactly 2.9% more than he had originally wanted, as a great victory.

"You would think he would be slightly sheepish. But he said 'we have succeeded quite spectacularly!' I would hate to see what happens when things go wrong!"

To be fair, Mr Cameron shot back. In the coalition, they were all one big happy family! "On this side it's all brotherly love!" he said sarkily.

Then there was a roll of thunder, discernible to me at least. Sir Peter Tapsell rose in his majesty. "Sh! Sh!" shouted Labour MPs. In Bayeux, a crack team of needleworkers were on standby to record the historic event in a tapestry. This was never going to be good for the prime minister. An arrow winged its lethal way towards his eye.

Sir Peter pointed out that it seemed the EU constitution could be changed at the request of the German chancellor. "Is it possible that a Bwitish pwime minister [Sir Peter has a slight speech impediment] might be given the same opportunity, so enabling him to give us the Wefewendum we were pwomised!"

Pwomised by whom? The Labour party or David Cameron? Like the Oracle at Delphi, Sir Peter is often deliberately ambiguous, but in this case, as so often, I think we may assume that it was directed at his own side.

There followed a splendid moment when Chris Bryant, a former Labour minister, scornfully pointed out that the prime minister had failed to persuade the Polish foreign minister, even though they had both been members of the Bullingdon Club at Oxford.

"The difference between the Rt Hon gentleman and myself," replied Mr Cameron, "is that when we were at Oxford together, he was a member of the Conservative Association and I wasn't."